damaged a further 1,500 properties. The flooding was accompanied by massive debris flows of mud, boulders, and downed trees, which surged out of the foothill canyons. Transport and communication were cut off for many days as roads and railroads were buried, and power, gas, and communication lines were cut. Dozens of bridges were destroyed by the sheer erosive force of floodwaters or by the collision of floating buildings and other wreckage. Some communities were buried as much as deep in sand and sediment, requiring a massive cleanup effort afterward. It took from two days to a week to restore highway service to most impacted areas. The Pacific Electric rail system, serving Los Angeles, Orange, San Bernardino, and Riverside Counties, was out of service for three weeks. Although the 1938 flood caused the most damage of any flood in the history of Los Angeles, the rainfall and river peaks were not even close to the Great Flood of 1862, the largest known flood by total volume of water. However, during the 1862 flood, the region was much less populated than it was in 1938. Los Angeles area About were flooded in Los Angeles County, with the worst hit area being the San Fernando Valley, where many communities had been built during the economic boom of the 1920s in low-lying areas once used for agriculture. In fact, many properties were located in old river beds that had not seen flooding in some years. Swollen by its flooded tributaries, the Los Angeles River reached a maximum flood stage of about . The water surged south, inundating Compton before reaching Long Beach, where a bridge at the mouth of the river collapsed killing ten people. To the west, Venice and other coastal communities were flooded with the overflow of Ballona Creek. The Los Angeles Times chartered a United Air Lines Mainliner to provide them an aerial view of flooding damage. The reporter remarked: "Disaster, gutted farmlands, ruined roads, shattered communications, wrecked railroad lines—all leap into sharp-etched reality from that altitude." Communities and mining operations in the San Gabriel Mountains such as Camp Baldy were destroyed, stranding hundreds of people for days. As many as 25 buildings were destroyed in the Arroyo Seco canyon, although due to a successful evacuation, no one was killed. Two Civilian Conservation Corps camps, three guard stations and a ranger station were destroyed, along with sixty campgrounds. Almost every road